Krebs on Security

In-depth security news and investigation

Posts Tagged: POS skimmer

Point-of-sale (POS) skimmers — fraud devices made to siphon bank card and PIN data at the cash register — have grown in sophistication over the years: A few months back, this blog spotlighted a professionally made point-of-sale skimmer that involved some serious hacking inside the device. Today’s post examines a comparatively simple but effective POS skimmer that is little more than a false panel which sits atop the PIN pad and above the area where customers swipe their cards.

In scams, as with most things in life, there is a certain elegance in simplicity. This is doubly true with ATM and credit card skimmer scams: The more components and electronics involved, the greater the chance that the fraud devices will malfunction, lose juice, or else be detected too quickly. In fact, some of the most elegant skimming attacks I’ve seen to date never even touched the cash machine, and relied on very basic components.

Recently, I encountered a fraudster selling a remarkably simple but brilliant POS skimming device that can be installed and removed in the blink of an eye. This video, which was produced by a fraudster who sells these devices for thousands of dollars on semi-private underground forums, shows a late-model Verifone point-of-sale device retrofitted with a skimmer overlay. The underside of the device (not pictured) includes a tiny battery and flash storage card that allows the fake PIN pad to capture the key presses, and record the data stored on the magnetic stripe of each swiped card.

Such a device would be an enticing buy for a crooked employee at a retail store. It might even be installed surreptitiously by thieves posing as customers at a retail establishment. Last month, this blog featured a story about several fraudsters in Florida who did just that, installing hardware-based register skimmers at Nordstrom department stores while co-conspirators distracted sales personnel.

If you hand your credit or debit card to a merchant who is using a wireless point-of-sale (POS) device, you may want to later verify that the charge actually went through. A top vendor of POS skimmers ships devices that will print out “transaction approved” receipts, even though the machine is offline and is merely recording the customer’s card data and PIN for future fraudulent use.

This skimmer seller is a major vendor on one of the Underweb’s most active fraud forums. Being a “verified” vendor on this fraud forum — which comes with the stamp of approval from the forum administrators, thus, enhancing the seller’s reputation — costs $5,000 annually. But this seller can make back his investment with just two sales, and judging from the volume of communications he receives from forum members, business is brisk.

This miscreant sells two classes of pre-hacked wireless Verifone POS devices: The Verifone vx670, which he sells for $2,900 plus shipping, and a Verifone vx510, which can be had for $2,500. Below is a video he posted to youtube.com showing a hacked version of the vx510 printing out a fake transaction approval receipt.

From the seller’s pitch: “POS is ‘fake’ and stores D+P [card data and PIN], prints out approved receipt or can be setup for connection error. Software to decrypt the data is provided. It keeps d+p inside memory for manual retrieval via USB cable.”

These types of hacked POS systems, known as “offline POS skimmers” in the Underweb, are marketed for suggested use by miscreants employed in seasonal or temporary work, such as in restaurants, bars or retail establishments.